Onychomycosis due to Aspergillus niger without black nail discoloration: A case report

A 39-year-old Caucasian male presented with a 5-year history of thickened toenail. The patient admitted that he used topical isoconazole nitrate twice daily for two months, without any improvement. The past medical history was unremarkable. The physical examination revealed subungual hyperkeratosis and onycholysis on the lateral side of the first toenail, onychoschizia of the second and fourth toenails, subungual hyperkeratosis of the fifth toenail. Our initial diagnosis was distal lateral subungual onychomycosis (Fig. 1). Therefore, we performed mycological culture of nail clippings of the first toenail using Sabouraud′s dextrose agar. Aspergillus niger was isolated (Fig. 2).